Are All-Nighters Bad for Your Health?

This content was created by the National Sleep Foundation


Why your last-minute study habits may be worse for you than you think.

Cramming for a test until sunrise or staying up all night to complete a work project may seem harmless, but the tactic could actually backfire. Students who pull all-nighters have greater difficulty concentrating and making decisions, as well as delayed reaction times, compared with their classmates who get a good night’s sleep. All of this can make your everyday performance more challenging, whether your need to ace a test or wow a client with your business presentation. Plus, a lack of shut-eye can worsen your memory, which means that all that time spent reviewing flash cards until 5:00am could end up being a waste of time.

The opposite is true when you get a good night's sleep after studying. Snoozing can help you perform better on an exam, because it gives your body a chance to process new information while your rest, so you'll remember it better on test day.

But your GPA or a promotion by your employer isn’t the only thing on the line when you pull an all-nighter; your health may also be affected. Sleep deprivation can lead to an increase of the stress hormone cortisol, which can weaken your immune system and make you more prone to catching an illness (and getting the flu isn’t a fun way to celebrate the end of finals!). Plus, a late-night study habit may also influence the scale. A lack of sleep is linked to weight gain, possibly because it increases your craving for junk food while also impairing your ability to realize when you’re full.

Of course, a late night here and there is inevitable for many students, and even for some adult workers who never managed to kick the habit in high school or college. While the occasional all-nighter won’t drastically affect your health, it’s best not to make a habit of it. Aim to get back to a regular sleep schedule immediately afterward so you can make up for any accumulated sleep debt, and consider taking a cue from your non-procrastinating peers on how to plan ahead next time so you don’t end up cramming all night long!